Helicoil problem

["Slack Alice" Simon]

They come out easily if you can unpick enough of the end to grab with long nosed pliers or side cutters.

Then they can be unwound out, they collapse a bit, and so loosen.

Try tapping the hole a bit deeper (you need the tap the correct size) before inserting a new one.

If you don't want to do that, cut the next insert short with a sharp pair of side cutters, de-burr the end with a small file before inserting.